WASHINGTON (AP) — Construction to upgrade North Korea’s main rocket launch pad should be complete by this fall, allowing Pyongyang to conduct a launch by year’s end if it decides to do so, a U.S. research institute said Thursday.

The U.S.-Korea Institute at the Johns Hopkins School of Advanced International Studies is basing its conclusions on commercial satellite imagery of the Korean west coast site of Sohae. The latest photo is from Aug. 8.